1. Field of the Invention
A drain stopper basins, and more specifically a magnetically actuated drain stopper.
2. Related Art
Basins, bathtubs, sinks and other varieties of receptacles (hereinafter collectively “basins”) are used in various applications to hold water or other liquids. Basins often include a drain passage through which liquid retained in the basin can be purged. Typically, the opening to the drain passage can be selectively closed by positioning a stopper in or over the opening. In many common configurations, the stopper is manually actuated through a lever-operated linkage to lift the head of the stopper away from the opening so that liquid (e.g., water) can run by gravity into the drain passage. Examples of prior art drain stopper assemblies manually actuated through a lever-operated linkage may be found in U.S. Pat. No. 6,341,391 to Cheng, issued Jan. 29, 2002 and U.S. Pat. No. 6,484,330 to Gray et al., issued Nov. 26, 2002. FIG. 1 illustrates a prior art basin and drain stopper assembly of the type actuated manually through a lever-operated linkage.
While prior art drain stopper assemblies like that shown in FIG. 1 are functional, all share the common trait of a control rod end positioned inside the drain passage. FIG. 2 is a view looking down the drain passage from above a basin, and showing the typical control rod end disposed to engage the stopper (not shown). This protruding end of the control rod is in the direct flow of liquid as it drains from the basin, thus making the rod end prone to catch and retain debris which, over time, can build up to eventually clog the drain. Moreover, the protruding control rod end impedes easy access to the P-trap in the drain passage below where clog tend to reside. Thus, an attempt to dislodge a clog in the P-trap with a snake or hook through the drain passage opening will be met with opposition by the control rod end. Still further, the control rod penetrates the drain pipe usually through a spherical compression joint, creating a potential leak path.
To address some of the shortcomings of prior art drain stopper assemblies like that shown in FIG. 1, the prior art has also taught to fashion a magnetically actuated drain stopper assembly. Examples of these types of devices may be found in U.S. Pat. No. 5,208,921 to Nicoll, issued May 11, 1993 and U.S. Pat. No. 5,640,724 to Holmes, issued Jun. 24, 1997. Such devices utilize a specially configured stopper having a magnet attached to its lower guide section. This stopper magnet interacts with a driver magnet supported outside the drain pipe. Magnetic flux interactions between the stopper and driver magnets cause the stopper to lift when the driver magnet is pulled up and to fall when the driver magnet is lowered. One particular advantage of a magnetically actuated drain stopper assembly is evident from FIG. 3 which is a top view of a drain passage as in FIG. 2 but notable by the absence of any protruding control rod end. The drain passage of a magnetically actuated drain stopper assembly is clear of any internal obstruction, thereby facilitating the drainage of liquids from the basin without exacerbating clogs, enabling unimpeded access to the P-trap with a snake or hook through the drain passage opening, and the absence of additional potential leak paths from a penetrating control rod.
Most if not all prior art style magnetically actuated drain stopper assemblies are configured so that the external driver magnet(s) is mounted on the drain pipe to slide linearly up and down. These are designed to maintain a relatively constant spacing between the driver and stopper magnets. In other words, there is a one-to-one (1:1) corresponding movement of the stopper in relation to the displacement of the driver magnet. This one-to-one relationship has many disadvantages. If the operator pulls upwardly too rapidly on the driver magnet, they can overcome the stopper magnet so that it does not lift. Stronger magnets than otherwise necessary may be used to help prevent this condition. Furthermore, a sliding motion is difficult to maintain in proper working order over a long period of time. The underside of a basin is typically clamp and neglected for long periods of time so that dirt build-up can go undetected. Mechanical systems that operate in this environment must be robust and not prone to malfunction in dirty conditions.
Thus, there is a need in the art for an improved magnetic stopper assembly for a basin drain that provides easier and greater access to the drain, that functions mare reliably, and that is not prone to malfunction.